jugad2 - Vasudev Ram on software innovation: PeeWee

Thursday, September 29, 2016

Publish Peewee ORM data to PDF with xtopdf

By Vasudev Ram

Peewee => PDF

Peewee is a small, expressive ORM for Python, created by Charles Leifer.

After trying out Peewee a bit, I thought of writing another application of xtopdf (my Python toolkit for PDF creation), to publish Peewee data to PDF. I used an SQLite database underlying the Peewee ORM, but it also supports MySQL and PostgreSQL, per the docs. Here is the program, in file PeeweeToPDF.py:

# PeeweeToPDF.py
# Purpose: To show basics of publishing Peewee ORM data to PDF.
# Requires: Peewee ORM and xtopdf.
# Author: Vasudev Ram
# Copyright 2016 Vasudev Ram
# Web site: https://vasudevram.github.io
# Blog: http://jugad2.blogspot.com
# Product store: https://gumroad.com/vasudevram

from peewee import *
from PDFWriter import PDFWriter

def print_and_write(pw, s):
    print s
    pw.writeLine(s)

# Define the database.
db = SqliteDatabase('contacts.db')

# Define the model for contacts.
class Contact(Model):
    name = CharField()
    age = IntegerField()
    skills = CharField()
    title = CharField()

    class Meta:
        database = db

# Connect to the database.
db.connect() 

# Drop the Contact table if it exists.
db.drop_tables([Contact])

# Create the Contact table.
db.create_tables([Contact])

# Define some contact rows.
contacts = (
    ('Albert Einstein', 22, 'Science', 'Physicist'),
    ('Benjamin Franklin', 32, 'Many', 'Polymath'),
    ('Samuel Johnson', 42, 'Writing', 'Writer')
)

# Save the contact rows to the contacts table.
for contact in contacts:
    c = Contact(name=contact[0], age=contact[1], \
    skills=contact[2], title=contact[3])
    c.save()

sep = '-' * (20 + 5 + 10 + 15)

# Publish the contact rows to PDF.
with PDFWriter('contacts.pdf') as pw:
    pw.setFont('Courier', 12)
    pw.setHeader('Demo of publishing Peewee ORM data to PDF')
    pw.setFooter('Generated by xtopdf: slides.com/vasudevram/xtopdf')
    print_and_write(pw, sep)
    print_and_write(pw, 
        "Name".ljust(20) + "Age".center(5) + 
        "Skills".ljust(10) + "Title".ljust(15))
    print_and_write(pw, sep)

    # Loop over all rows queried from the contacts table.
    for contact in Contact.select():
        print_and_write(pw, 
            contact.name.ljust(20) + 
            str(contact.age).center(5) + 
            contact.skills.ljust(10) + 
            contact.title.ljust(15))
    print_and_write(pw, sep)

# Close the database connection.
db.close()

I could have used Python's namedtuple feature instead of tuples, but did not do it for this small program.

I ran the program with: